Effect of Processing Routes on the Microstructure and Thermoelectric Properties of Half-Heusler TiFe0.5Ni0.5Sb1?xSnx (x = 0, 0.05, 0.1, 0.2) Alloys

Sn-doped TiFe0.5Ni0.5Sb1?xSnx (x = 0, 0.05, 0.1, 0.2) were synthesized by vacuum arc melting (VAM). In addition to the half-Heusler phase, secondary phases of Fe–Sb-rich compound and Ti-rich compounds obtained after VAM. The alloys then subjected ball milling for 1 h 5 h. Ball 1h led microcrystalline grains, while that nanocrystalline grains. followed spark plasma sintering (SPS) at 1173 K significant reduction in size microstructure. undoped sample exhibited a ZT 0.008 873 both 5h BM-SPS samples.